Because a dog house is relatively small, building its foundation will require neither a great amount of materials nor a lot of time. These instructions are for a dog house that's already built.

Step 1 - Measure the Dog House

Measure the length and width of the dog house with the tape measure. To each of these dimensions, add 6 to 8 inches on each end (12 to 16 inches total). Thus if the house measures 36 inches by 48 inches, plan to make the foundation 48 inches by 60 inches.

Step 2 - Lay out the Foundation Area

Determine where you will situate the foundation in your yard. Pick an area that is as level as possible. Measure along the ground the dimensions you calculated in the previous step. Mark the rectangle on the ground. This rectangle is where you will dig out the dirt to lay the concrete.

Step 3 - Dig the Area

With the shovel, dig out a rectangle that is larger than the foundation by 2 inches per side. If the foundation will be 48 by 60 inches, dig out an area that is 52 by 64 inches. Dig about 4 inches deep and make the bottom as flat as possible. Use a level to check your work.

Step 4 - Frame the Foundation

Because the foundation is so small, you can prebuild the frame and set it in the ground. Cut four lengths of the lumber.

Two-by-four lumber is actually 1 3/4 x 3 3/4 inches. You need to factor in the thickness of the wood. If you want the actual dimensions of the concrete to be 48 x 60 inches, cut the short ends to 48 inches and the long ends to 60 inches plus the thickness of two pieces of wood (–1 3/4 x 2 = 3 1/2). Thus, for the measurements above, you should cut the long ends to 63 1/2 inches each.

Using woodscrews, fasten the rectangle on a flat surface.

Step 5 - Secure in the Ground

Lay the frame in the ground. Using the level and hammer, work it in so it is completely level and the same height as the grass or topsoil. Use several stakes around the outside of the frame to hold it in place.

Step 6 - Mix the Concrete

Open a bag of premix concrete into the wheelbarrow and begin to add water. Use the garden hoe to mix it. The concrete should be neither too soupy nor too thick.

Once you've completely mixed it, begin to shovel it in between the frame. Mix as many bags as you need to fill the hole. Once all of the concrete is in place, level it to the top of the frame and smooth it out with the trowel.

Don't be afraid to spend a little time on this step. You want all stones worked out so the wet slab of concrete is perfectly level.

Step 7 - Cover and Let Sit

Let the slab sit for the remainder of the day. Make sure nothing disrupts it. When you retire for the evening, cover the slab loosely with plastic so it retains moisture. In a day or two it should be completely dry.

Step 8 - Remove the Frame

After the slab is totally dry, remove the frame. Remove the screws and lightly knock off the pieces of wood with a mallet or hammer. Fill in the hole with dirt and set the dog house atop the new foundation.

As an alternative, you can add four bolts to the hardening concrete and later secure the dog house with the bolts. If you do this, make sure the bolts are entirely plumb.